Code sample for php download file

 
<?php 
$file = 'monkey.gif'; 

if (file_exists($file)) { 
header('Content-Description: File Transfer'); 
header('Content-Type: application/octet-stream'); 
header('Content-Disposition: attachment; filename='.basename($file)); 
header('Content-Transfer-Encoding: binary'); 
header('Expires: 0'); 
header('Cache-Control: must-revalidate, post-check=0, pre-check=0'); 
header('Pragma: public'); 
header('Content-Length: ' . filesize($file)); 
ob_clean(); 
flush(); 
readfile($file); 
exit; 
} 
?> 

The above code is the download code
Next, post a code to preview the pdf file online

 
<?php 
public function fddAction() 
{ 
// get attachment location 
$attachment_location = $_SERVER["DOCUMENT_ROOT"] . "/pdf/fdd/sample.pdf"; 

if (file_exists($attachment_location)) { 
// attachment exists 

// send open pdf dialog to user 
header('Cache-Control: public'); // needed for i.e. 
header('Content-Type: application/pdf'); 
header('Content-Disposition: inline; filename="sample.pdf"'); 
readfile($attachment_location); 
die(); // stop execution of further script because we are only outputting the pdf 

} else { 
die('Error: File not found.'); 
} 
} 
?>